Circular knitting machine for making uniform loops



March 1, 1966 R. SCHMIDT 3,237,430

CIRCULAR KNITTING MACHINE FOR MAKING UNIFORM LOOPS Filed Oct. 8, 1962 2 Sheets-Sheet 1 INVENTOR R cfiwm (SM/ 124i BY L R. SCHMIDT March 1, 1966 2 Sheets-Sheet 2 Filed Oct. 8, 1962 FIG. 2

INVENTOR. Wm/2% g 051 400? FIG. 3

United States Patent 6 Claims. (a. 66-19) The present invention relates to a circular knitting machine for making uniform loops, and more particularly to a circular knitting machine of the type in which a set of cylinder needles cooperates with a set of dial needles to knit a rib fabric.

In conventional knitting machines of this type, the socalled sinker loops do not have exactly the same shape as the so-called needle loops. It will, of course, be understood that no sinkers are provided in circular knitting machines using dial needles with which the present invention is concerned.

On a knitting machine of the Cotton type, a plain fabric can be knitted in which all loops have exactly the same shape and size. The thread is looped by the sinkers, and then formed into loops of the same length by the dividers. It is not possible to obtain such perfect uniform loops on conventional knitting machines employing cylinder needles and dial needles in which the loops on the face of the knitted ribbed fabric are made by the cylinder needles, and the loops on the back of the fabric are made by the dial needles.

It is one object of the present invention to improve a circular knitting machine having cylinder needles and dial needles so that all loops of a rib fabric knitted thereon are of equal shape, width, and size.

Another object of the present invention is to improve a circular knitting machine in such a manner that the socalled sinker loops have the same width, shape, and size as the so-called needle loops.

Another object of the invention is to provide a circular knitting machine in which the loops formed by the dial needles have the same shape and size as the loops formed by the cylinder needles.

It is also an object of the present invention to provide a circular knitting machine, which, although corresponding in its construction to conventional machines, has particular dimensions which result in the knitting of a rib fabric composed of uniform loops.

With these objects in view, one embodiment of the present invention comprises a set of cylinder needles disposed along a cylindrical surface spaced from each other a first distance, and a set of dial needles movable between an advanced position cooperating with the cylinder needles and a retracted position in which the ends of the dial needles are located along a circle, for example, the circular inner edge of the dial.

In accordance with the present invention, this circle is spaced from the cylindrical surface along which the cylinder needles move, a second distance which is substantially equal to the first distance divided 'by 1.3.

As a result, the loops formed by the dial needles and by the cylinder needles and the sinker loops connecting adjacent loops formed by the dial needles and cylinder needles have substantially the same shape, width and size so that a uniform rib fabric is knitted on the machine.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be 3,2314% Patented Mar. 1, 1966 best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic view illustrating two adjacent needle loops and a sinker loop on an enlarged scale;

FIG. 2 is a schematic view illustrating the perfect loop formation of a fabric made on the improved machine of the present invention by cylinder needles and dial needles;

FIG. 3 is a fragmentary perspective view illustrating the successive operations of the cylinder and dial needles; and

FIG. 4 is a fragmentary axial sectional view taken on line IVIV in FIG. 3.

Referring now to the drawings, and more particularly to FIG. 1, a plain knitted fabric is composed of needle loops 4 and 5 and of sinker loops 6 of opposite curvature. The portion 1 of the needle loop may be called the head which is connected by lateral legs 2 to the foot pertions 3 and 3 which pass through needle loops to form the sinker loop.

In a knitting machine of the Cotton type, in which sinkers are used for making a plain fabric, the loops 4- and 5 are called needle loops, and the opposite loop 6 is called a sinker loop, which terminology is maintained although no sinkers are provided in a circular knitting machine of the type with which the present invention is concerned. In the Cotton type knitting machine, the sinker loops and needle loops are of exactly the same shape and size, and a plain fabric is made in which the loops 4 and 5 pass forwardly through the old loops 4' and 5'. FIG. 2 shows a perfect ribbed fabric made by cylinder needles and dial needles. Four wales A, B, C and D are illustrated of which wales A and C are made by the cylinder needles and wales B and D are made by the dial needles. The loops of the stitches 7' of the wales A and C of the course E pass in forward direction through the loops of the stitches 7 of the preceding course F while the loops of the stitches 8' of the course E pass in rearward direction through the loops of the stitches 8 of the course F. The Wales A, C are located on the face of the fabric and the wales B, D are located on the back of the fabric.

The improvement of the present invention results in a fabric in which all stitches 7 and 8 have the same shape and size and particularly in which the heads 1 of all loops have the same shape, size and curvature as the arcuate thread portions X formed by the foot portions 3 and 3. In conventional knitting machines employing cylinder needles and dial needles these arcuate portions are larger than the arcuate head portions 1, and the shape and size of the arcuate portions 3, 3 of adjacent walls, as well as the shape and size of the heads 1 of adjacent wales are different, resulting in an undesirable appearance of the knitted fabric which locks the uniform smooth appearance of a fabric made on a Cotton type knitting machine.

This perfect loop shape of all loops of a rib'bed fabric is obtained in accordance with the present invention by the construction illustrated in FIG. 4. The needle cylinder 9 has inner Vertical guide channels for guiding the cylinder needles 11 for vertical movement along a cylindrical surface 9a which has a radius R9. The cylinder needles 11 are raised and lowered for catching the thread and for forming loops by cams engaging the butts of needles 11, not shown.

The dial 10 has a circular inner edge whose radius R10 is less than the radius R9 of the inner cylindrical surface by a distance a. Dial needles 12 are mounted on the dial 10 for movement in a horizontal plane defined by a surface of dial 10. In the retracted position shown in FIG. 4, the ends of needles 12 are located at the circular inner edge 10a of the dial and along a circle. It is evident that the inner ends 12a of the dial needles are spaced the distance a from the vertical cylindrical surface along which the cylinder needles 11 move. Dial needles 12 are inwardly moving in radial direction to a position cooperating with the cylinder needles 11 for forming loops.

Referring now to FIGS. 3 and 4, the needle cylinder 9 and the dial 10 turn simultaneously about the common vertical axis Y in the direction of the arrow R. The stitch and dial cams operate the cylinder needles and dial needles so that the needles move successively to the advanced positions SE and SE, respectively. The loops or stitches 7, 8 move to a position rearward of the open tongues, 11', 12. The thread guide FF places the thread FA in the path of the needles so that the thread is caught by the hooks of the travelling needles 11 and 12. During the retraction of the needles to the retracted positions SA and SA, respectively, the thread is formed into new loops 7 and 8 which are drawn through the old loops 7 and 8. The length of the thread. portions between the loops 7 of the cylinder needles 11 and the loops 8 of the dial needles 12 determines the size and shape of the arcuate loop portion X consisting of the thread portions 3, 3.

As shown in FIG. 4, a loop 8 is held on the dial needle 12, and the loop 7 by the cylinder needle 11. The thread portion X connecting the adjacent loops 7 and 8 carries together with the following thread portion X the preceding loop 8", The thread portion X carries together with the following thread portion X" the preceding cylinder loop 7".

As shown in FIG. 3, the cylinder needles 11 are spaced in circumferential direction of cylinder 9 a distance b along cylindrical surface 9a, and dial needles are spaced the same distance 12 but are offset with respect to the cylinder needles.

As is well known to those skilled in the art, it is conventional to provide 16), or 12, or 14, or 16, or 18 needles per inch in circumferential direction, so that the distance b between the cylinder needles 11 is unit divided by the Needles per inch Distance 12,

Distance a, mm. mm.

In accordance with the present invention, the distance 12 divided by the distance a should be 1.3, or in other words, the distance a between the inner edge 10a and the inner cylindrical surface 9a is equal to the distance b between two adjacent cylinder needles 11 divided by 1.3.

The third column of the above table gives the distances a in accordance with the preesnt invention for different arrangements of the cylinder needles.

For example, in one embodiment of the invention in which 16 cylinder needles 11 are provided along one inch in circumferential direction of the inner cylindrical sur face 9a spaced along the same circumferential distances 1.58 mm., the inner cylindrical edge 10a of the dial 10 is spaced between 1.2 mm. and 1.3 mm. from the inner cylindrical surface 9a and from the cylinder needles 11.

It has been found that if the dial 10 and the cylinder 9 are constructed and dimensioned in accordance with the present invention all sinker and needle loops made by the cylinder needles and dial needles have the same width, shape and size so that a uniform fabric is produced.

This distance is about smaller than the corresponding distance in knitting machines of this type according to the prior art which, for example, provide a distance a between 1.8 and 2 mm. for machines having 16 needles per inch.

When the machine is constructed and dimensioned in accordance with the present invention, the arcuate loop portions X, and the heads of the loops 7 and 8, all have the same shape, width and size.

The raising or lowering of the dial 10 relative to the cylinder 9 required for varying the length L of the stitches has no influence on the perfect loop formation obtained in accordance with the present invention.

The improvement of the present invention is entirely unobvious and surprising, since those skilled in the art of knitting machines did not consider it possible to reduce the distance a without obstructing the operation of the machine by thread and fabric caught in the gap between the dial and the cylinder. Due to the fact that entirely uniform loops are produced by the improvement of the present invention, the reduced gap is suflicient to permit the passage of the fabric without causing any disturbances.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of circular knitting machines different from the types described above.

While the invention has been illustrated and described as embodied in a circular knitting machine in which the gap between the dial and the cylinder is substantially smaller than in conventional knitting machines of this type, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by letters Patent is:

1. In a circular knitting machine, in combination, a set of cylinder needles disposed along a cylindrical surface spaced from each other in a first distance, and a set of dial needles movable between an advanced position cooperating with said cylinder needles and a retracted position in which the ends of said dial needles are located along a circle spaced from said cylindrical surface a second distance which is substantially equal to said first distance divided by 1.3 whereby the loops formed by said dial needles and said cylinder needles have substantially the same shape, width, and size so that a uniform rib fabric is knitted on the machine.

2.1m a circular knitting machine, in combination, a set of cylinder needles disposed along a cylindrical surface spaced from each other one sixteenth inch, and a set of dial needles movable between an advanced position cooperating with said cylinder needles and a retracted position in which the ends of said dial needles are located along a circle spaced from. said cylindrical surface between 1.2 mm. and 1.3 mm. whereby the loops formed by said dial needles and said cylinder needles have substantially the same shape, width, and size so that a uniform rib fabric is knitted on the machine.

3. In a circular knitting machine, in combination, a

ported on said dial and by cylinder needles guide in said guide channels have substantially the same shape and size so that a uniform rib fabric can be knitted on the machine.

4. In a circular knitting machine, in combination, a needle cylinder having a set of vertical guide channels whose bottom surfaces are disposed along a vertical cylindrical surface spaced from each other a first distance in circumferential direction; a set of cylinder needles respectively mounted in said guide channels for vertical movement; a dial having a circular inner edge extending along a circle having a greater diameter than said cylindrical surface and having its center located on the axis of said cylindrical surface, said circle being spaced from said cylindrical surface in radial direction with respect to said axis a second distance which is substantially equal to said first distance divided by 1.3; a set of dial needles mounted on said dial for movement in radial direction between an inner advanced position cooperating with said cylinder needles and a retracted position in which the inner ends of said dial needles are located along said circular inner edge of said dial whereby loops formed by said dial needles and by said cylinder needles have substantially the same shape, width, and size so that a uniform rib fabric is knitted on the machine.

5. In a circular knitting machine, in combination, a set of cylinder needles disposed along a cylindrical surface spaced from each other a first distance, and a set of dial needles movable between an advanced position cooperating with said cylinder needles and a retracted position in which the ends of said dial needles are located along a circle inwardly spaced from said cylindrical surface a second distance which is in a predetermined ratio to said first distance and smaller than the same, said sec- 0nd distance being selected in such a manner that yarn sections between adjacent cooperating cylinder needles and dial needles are of a length having such a relation to the length of yarn sections of which needle loops are formed that loop portions formed of said first mentioned yarn sections have essentially the same shape, width, and size as the head portions of the needle loops so that a uniform rib fabric is knitted on the machine.

6. In a circular knitting machine, in combination, a set of cylinder needles disposed along a cylindrical circuit spaced from each other a first distance, and a set of dial needles movable between an advanced position cooperating with said cylinder needles and a retracted position in which the ends of said dial needles are located along a circle inwardly spaced from said cylindrical surface a second distance which is substan tially equal to said first distance divided by 1.3, the coefficient 1.3 being selected in such a manner that yarn sections between adjacent cooperating cylinder needles and dial needles are of a length having such a relation to the length of yarn sections of which needles loops are formed that loop portions formed of said first mentioned yarn sections have essentially the same shape, width, and size as the head portions of the needle loops so that a uniform rib fabric is knitted on the machine.

References Cited by the Examiner UNITED STATES PATENTS 7/1917 Carter 66-19 3/1957 Larkin 66-115 X 

5. IN A CIRCULAR KNITTING MACHINE, IN COMBINATION, A SET OF CYLINDER NEEDLES DISPOSED ALONG A CYLINDRICAL SURFACE SPACED FROM EACH OTHER A FIRST DISTANCE, AND A SET OF DIAL NEEDLES MOVABLE BETWEEN AN ADVANCED POSITION COOPERATING WITH SAID CYLINDER NEEDLES AND A RETRACTED POSITION IN WHICH THE ENDS OF SAID DIAL NEEDLES ARE LOCATED ALONG A CIRCLE INWARDLY SPACED FROM SAID CYLINDRICAL SURFACE A SECOND DISTANCE WHICH IS IN A PREDETERMINED RATIO TO SAID FIRST DISTANCE AND SMALLER THAN THE SAME, SAID SECOND DISTANCE BEING SELECTED IN SUCH A MANNER THAT YARN SECTIONS BETWEEN ADJACENT COOPERATING CYLINDER NEEDLES AND DIAL NEEDLES ARE OF A LENGTH HAVING SUCH A RELATION TO THE LENGTH OF YARN SECTIONS OF WHICH NEEDLE LOOPS ARE FORMED THAT LOOP PORTIONS FORMED OF SAID FIRST MENTIONED YARN SECTIONS HAVE ESSENTIALLY THE SAME SHAPE, WIDTH, AND SIXZE AS THE HEAD PORTIONS OF THE NEEDLE LOOPS SO THAT A UNIFORM RIB FABRIC IS KNITTED ON THE MACHINE. 